Multiparticulate drug delivery systems are dosage form, which consists of multiple small discrete units, where each unit exhibits some intended characteristics. Multiparticulates are well-known dosage forms that comprise a plurality of particles for different therapeutic use of the drug.
Modified release formulation aims at minimizing the peak-to-trough variation in drug plasma levels that are associated with conventional frequent dosage regimes.
Several attempts have been made to develop formulations that provide a zero-order release of the drug compound. Most of the modified release formulations today offer the release profile as a zero order, first order or have a delayed release profile. Combination of different types of release i.e. either extended-release or delayed-release and combinations thereof can be achieved by multiparticulates in the dosage form. However these also offer difficulty in achieving the right combination of pellets/particles or where a very high dose needs to be given.
U.S. Pat. No. 4,892,741 discloses solid medicament preparation having a long-lasting action in the form of a press coated tablet which containing dihydropyridine. The press coated tablet comprises (a) a core which contains a dihydropyridine in rapid-release form, and (b) a coat around the core, the coat containing a dihydropyridine in slow-release form.
US2006210631 discloses a multi-particulate, modified-release pharmaceutical composition for the oral administration of an active ingredient to the colon, said particles comprising a core comprising an active ingredient or a pharmaceutically acceptable salt or ester thereof, and optionally one or more excipients; a first coating applied to the surface of the core, wherein said first coating is insoluble in gastric juice and in intestinal juice below pH 7, but soluble in colonic intestinal juice; and a second coating applied to the surface of the first coating.
Studies have shown that there are adverse effects with the coat-core systems compared to other drug delivery systems. Further, the core-coat technology requires the use of specialized equipment thereby rendering an expensive process of manufacture.
Therefore, there still exists a need to formulate modified release formulations containing two different portions of active ingredient which will provide for modified release of the active ingredient and which will have reduced or no adverse effects compared to prior art compositions. There also exists a need to develop process which could be simple and cost effective and would not involve any tedious techniques.
There exists a need for an improved multiparticulate formulation that would improve the bioavailability and release rate and would ameliorate the drawbacks of prior art compositions.